His mother, Emma Karoline Johanna Geiese (1869–1904) died of diabetes while Hans-Georg was four years old, and he later noted that this may have had an effect on his decision not to pursue scientific studies.

Jean Grondin describes Gadamer as finding in his mother "a poetic and almost religious counterpart to the iron fist of his father".

He defended his dissertation The Essence of Pleasure in Plato's Dialogues (Das Wesen der Lust nach den Platonischen Dialogen) in 1922.

[11] Shortly thereafter, Gadamer moved to Freiburg University and began studying with Martin Heidegger, who was then a promising young scholar who had not yet received a professorship.

[13] In 1933 Gadamer signed the Vow of allegiance of the Professors of the German Universities and High-Schools to Adolf Hitler and the National Socialistic State.

[15] From an SS-point of view Gadamer was classified as neither supportive nor disapproving in the "SD-Dossiers über Philosophie-Professoren" (i.e. SD-files concerning philosophy professors) that were set up by the SS-Security-Service (SD).

The level of Gadamer's involvement with the Nazis has been disputed in the works of Richard Wolin[17] and Teresa Orozco.

[27] It was during this time that he completed his magnum opus, Truth and Method (1960), and engaged in his famous debate with Jürgen Habermas over the possibility of transcending history and culture in order to find a truly objective position from which to critique society.

[28] In 1981, Gadamer attempted to engage with Jacques Derrida at a conference in Paris but it proved less enlightening because the two thinkers had little in common.

On the one hand, he was critical of modern approaches to humanities that modeled themselves on the natural sciences, which simply sought to "objectively" observe and analyze texts and art.

On the other hand, he took issue with the traditional German approaches to the humanities, represented for instance by Friedrich Schleiermacher and Wilhelm Dilthey, who believed that meaning, as an object, could be found within a text through a particular process that allowed for a connection with the author's thoughts that led to the creation of a text (Schleiermacher),[34] or the situation that led to an expression of human inner life (Dilthey).

Gadamer intended Truth and Method to be a description of what we always do when we interpret things (even if we do not know it): "My real concern was and is philosophic: not what we do or what we ought to do, but what happens to us over and above our wanting and doing".

For Gadamer, these prejudices are not something that hinders our ability to make interpretations, but are both integral to the reality of being, and "are the basis of our being able to understand history at all.

[43] Ultimately, for Gadamer, the most important dynamic of conversation as a model for the interpretation of a text is "the give-and-take of question and answer.

The most profound of these is the formulation of the dialogic coordinates, a standard set of prerequisite communication elements necessary for inciting dialogue.

Indeed, while Truth and Method became central to his later career, much of Gadamer's early life centered on studying Greek thinkers, Plato and Aristotle specifically.

In the Italian introduction to Truth and Method, Gadamer said that his work on Greek philosophy was "the best and most original part" of his career.

[46] His book Plato's Dialectical Ethics looks at the Philebus dialogue through the lens of phenomenology and the philosophy of Martin Heidegger.